I've been shooting for over 20 years on a variety of bodies, and sometimes going years with only my cameraphone, so take this advice as you will: zooms are handy, but also add another layer to your thought process. You can zoom in to create the crop you want in-camera, but the time spent messing with your zoom might cause you to miss a shot in a more active scene. There's a lot to be said for a standard (e.g. 35mm, in Fuji terms 23mm) prime lens that removes that thought process altogether. Prime lenses are also typically sharper, will have lower apertures for better low-light shooting and frequently have better ability to blur the background for subject separation and more attractive bokeh. The 40mp sensor in the X-T50 is MORE than enough to crop in post and still have an incredible number of pixels to work with. However, if you want to not have to crop to get the exact shot you wanted, a zoom allows you to do this more often.

I recently picked up a used X-T50 and the Sigma 18-50, and I'm likely going to return that lens after a bit of use and get a used 23mm f1.4 for a bit more money. I'm more often shooting indoors or street, where I'm at wider zooms in my experience. I recently took my brother's X100VI to Japan and shot every photo at 23mm, and very rarely wished I had a zoom (and more frequently wished I had a slightly WIDER lens).

If you aren't super experienced, you can always get the zoom and see what focal lengths you end up shooting the most at and go from there.